I've created a simple sketch which puts the unit to sleep after 10 seconds. I've hooked up a MM in series with 8 AA batteries in series. The batteries are rated at 2500mAh. Let's assume the rating is correct.
When I power on the unit in "normal" mode I get a reading of 40.6 and in "sleep" mode I get a reading of 25.9
Now I'm a bit embarrassed to ask this but what units are those in? If I set the dial to 20m, I get a value of 1, so I'm guessing that the reading is "above" 20mA", and setting the dial tp 200M gives me the readings above. So does that mean I'm reading 40.6mA and 25.9mA respectively?
Since I'm running in series, the capacity doesn't change, correct? so 8 batteries would give me 12V, while 4 batteries would be 6V, yet they would still have the same capacity of 2500Ah?
So is the calculation 2500mAh / 25.9 mA = 96.5 hours correct? That is just over 4 days and seems kind of low for something in sleep mode, especially because there are sites that claim in sleep mode you can get over a year off a pair of AA batteries.
Are my calculations correct? Did I miss a few decimal points?
#include <avr/sleep.h>
void goToSleep()
{
set_sleep_mode(SLEEP_MODE_PWR_DOWN);
sleep_enable();
sleep_mode();
sleep_disable();
}
void setup()
{
Serial.begin(9600);
}
void loop()
{
delay(10000); //wait so a VIN reading can be taken on the MM
goToSleep(); //now read VIN in sleep mode
}
mA would seem correct but you do not say what your hardware is which is kind of important.
In the article you linked, he totally ignores the current drawn by the regulators and the power LED, (yet he talks of blinking LEDs). Your measurements and calculations sound right to me.
Don't believe everything you read in people's blogs.
You could have asked this in your original thread rather than start a new one. And I already mentioned the regulator and LED current consumption there anyway. (Didn't you believe me?)
If you really want to reduce current consumption, use a stand-alone chip, not an Arduino board.
And as boardburner2 points out, you still haven't said which Arduino, in either of your threads.
Please read this on the current draws on sleep mode and how to save power on sleep mode.
OldSteve:
In the article you linked, he totally ignores the current drawn by the regulators and the power LED, (yet he talks of blinking LEDs). Your measurements and calculations sound right to me.
Don't believe everything you read in people's blogs.
You could have asked this in your original thread rather than start a new one. And I already mentioned the regulator and LED current consumption there anyway. (Didn't you believe me?)
If you really want to reduce current consumption, use a stand-alone chip, not an Arduino board.
And as boardburner2 points out, you still haven't said which Arduino, in either of your threads.
No I believed you, I just thought this was unique enough a question for a new topic. Sorry bout that.
Forgot to say, I'm using a Sunfounder Uno board. I will probably switch later once I get the concept solid.
ARGHH.. Hate the 5 minute limit
FutureTense:
No I believed you, I just thought this was unique enough a question for a new topic. Sorry bout that.
No problem.
Forgot to say, I'm using a Sunfounder Uno board. I will probably switch later once I get the concept solid.
Yeah I thought it might be a UNO. Once you get through development, you could just pluck the chip out and put it on a breadboard to conserve power.
Pluck out the chip? I'm unfamiliar with the concept? Could you suggest a guide on this? Or even a chip I could purchase? I'm getting very close now I think.
Here is the guide on How to make an Arduino-compatible minimal board